In this sentence:
I’ve throw back a lot of orange juice.
What does to “throw back (orange juice)” mean?
Answer
In that particular sentence, it means drunk.
In that the person has “thrown back” a lot of orange juice, thrown the juice to the back of their throat, i.e. tipped their head back and drunk the juice.
Attribution
Source : Link , Question Author : mko , Answer Author : Orbling